Research On Optimal Capacity Configuration And Optimal Economic Operation Of Grid-connected Wind/Photovoltaic/Storage Microgrid

With the rapid development of social and the exhaustion of traditional energy,coupled with the international environmental awareness caused by environmental pollution,renewable energy has attracted more and more attention.Microgrids as an important part of smart grid can coordination control various distributed energy to meet the users need and solve problems such as consumption of renewable energy.Microgrids has attracted great attention and developed rapidly.The volatility and randomness of renewable energy such as wind and light bring major challenges to the economy and stability of microgrids.Reasonable allocation of distributed power supply capacity such as wind,photovoltaic and storage battery in grid-connected wind/optical/storage microgrids can not only reduce the initial investment cost and operation maintenance cost of microgrids,but also improve the self-equilibrium of power supply in microgrids,and improve the safety of microgrids.The capacity optimization configuration method of grid-connected microgrids base on the improved multi-verse algorithm(MVO)is proposed in this paper.Firstly,according to the output characteristics of wind turbines,photovoltaic and storage batteries,the mathematical models for power output are built respectively.Secondly,the grid-connected wind/photovoltaic/battery-storage microgrids of multi-objective optimization model are established which containing levelized cost of energy,renewable energy efficiency and carbon emissions treatment cost.The model is set up for the economy,reliability,and environmental protection of the microgrid as the optimization goal.The analytic hierarchy process is used to solve multi-objective weights assignment problem.Through mandatory score thought to determine the degree of importance between multi-objective,and then to lower the subjectivity of judgement matrix elements.At the same time,the constraints on the system power balance,the output of distributed power supply,the transaction situation with the power grid and the utilization rate of renewable energy are set,and microgrid evaluation indexes including self-balancing rate,load loss rate,light and wind discard rate are established.In addition,according to the optimization model,an operation strategy is designed to improve the operation of microgrids which takes into account the grid power demand response.The service life of the energy storage battery is improved by comprehensively considering the system power difference and the energy storage battery state of charge.And then,a novel heuristic algorithm called MVO with few parameters and simple structure is introduced to solve the capacity allocation of microgrids.A wormhole existence probability with exponential self-adaptive growth is proposed to solve the problems of MVO such as easy to local optimum and slow convergence rate in the late stage of solution.And the ergodic property of chaotic search and the jump property of Levy flight strategy are used to improve the search method of MVO,the improved multiverse algorithm is chaos-levy flying multi-verse algorithm(CLMVO).Finally,the wind and solar resource in the eastern coastal area of China are taken as an example.The influence of government subsidies,time-of-use electricity price and carbon emission treatment cost coefficient on the optimal allocation are discussed respectively.MATLAB simulation results verified the rationality of the proposed method.The economic optimization operation method of microgrids base on CLMVO is proposed.First of all,an optimized operation model with the goal of minimizing the daily operation cost of the microgrids is established.In the model,transaction costs with the grid,operation maintenance costs and government subsidies for renewable energy power are considered,and the system operation constraints are defined.Secondly,a microgrids economic optimization strategy based on the time-of-use electricity price is proposed.The particle swarm optimization algorithm(PSO)and CLMVO are used under different operation strategies to realize the economic optimization of microgrids.Finally,the advantages of the CLMVO and the economy of the proposed operation strategy are proved by MATLAB simulation.